DVD-VR
As if the DVD format didn't have enough suffix tags to set the types of media apart from one another, the -VR and +VR tags are often ones that throw even more confusion into the mix.
There are several differences between the DVD-VR and the DVD+VR formats.
DVD-VR defines a logical format for video recording on specified disk formats such as DVD-R, DVD-RW and DVD-RAM, including the dual layer version of each. DVD-VR is not video compliant and will not play on every DVD player. Recently, newer DVD players as well as the Sony Playstation 2 have begun support for media recorded in the DVD-VR standard.
The DVD-VR standard allows recording manufacturers to have up to 99 titles per disk, multiple recording paths for variable playback choices depending on user interaction, Frame accurate editing for splitting purposes, video and data can co-exist on one disk, and Title and disk protection.
DVD+VR defines a logical format for recording on DVD+R, DVD+RW and DVD+RAM media. Contrary to its counterpart, it will not support dual layer formatted media.
The DVD+VR standard allows recording manufacturers to have up to 48 separate recordings per disk, playback on most standard DVD players, slot model recording with +RW media meaning if a recording is deleted, an additional recording of the same length can be put in its place, similar to tape recordings. Additionally, DVD+VR allows for bookmarks, chapter marks and playlists and version 2 of the standard allowed for video and data to co-exist on one disk.